A module is known from U.S. Pat. No. 5,252,914 which can be connected to such a system,
In electronic telecommunications equipment (e.g. switching exchanges) it is often necessary to check and test the behavior of the equipment or of parts thereof, both during the testing phase and during its regular operation. One of the tests carried out on the system consists in creating fault conditions and in monitoring and analyzing the response of the equipment. The fault condition is generally obtained by forcing some points of the equipment to a pre-set signal level, e.g. corresponding to logic 0 or logic 1, depending on the manufacturing technology employed for the logic circuits mounted on the module. Other tests may require injecting current noisew.
Hereinafter, the terms "actuation" (with no other specifications) or "signal insertions" shall be used to indicate both fault actuation and noise injection.
Tests need to be automated, and this requires that the equipment parts to be tested (hereinafter referred to as "modules") may be associated, at least temporarily, with interfacing means which on the one hand are driven by a testing and diagnosing system sending the signal insertion commands in a programmed fashion, and which on the other hand transfer the responses of the modules to the testing and diagnosing system. During the tests it is necessary to obtain conditions exactly corresponding, from the electrical point of view, with those which may occur during equipment operation, the normal operation of the equipment must not be disturbed in the absence of signal insertion and, conversely, the insertion commands and the responses must not be altered by signals present in a module under test. Moreover, mounting the interface means on the module must not require modifications to the construction or design of the module.
In the above-mentioned prior art In U.S. Pat. No. 5,252,914 which concerns a transceiver on a circuit board with a series of modules, diagnosis is carried out by coupling test equipment to some pins of the permanent connectors of the circuit board and additional pressure pins placed so as to provide for connections with the input and output pins of the modules on the board. The diagnosis facilities are thus restricted to what can be tested by contacting these pins.